IN THEIR RELATION TO HORTICULTURE. 75 



plant level with the surface, and to give the roots a horizontal direc- 

 tion. In cases where the good soil is only of very moderate thickness, 

 and where the subsoil is a ferruginous gravel, or a stiff cold clay, it is 

 not only necessary to drain the ground and plant upon the surface, 

 but the trees should be set on the top of mounds from six inches to 

 a yard above the surrounding level, and from four to eight feet in 

 diameter ; the bottom of these mounds being covered with some hard 

 substance, such as stone, slate, &c., to prevent the roots descending, 

 and to lead them out as it were in a horizontal direction. No manure 

 whatever should be incorporated with the soil, unless it should be very 

 poor indeed : but it may be applied as a mulching round the mound, 

 which will tend to keep the roots sufgciently moist and also near the 

 surface. If these points were attended to, we should hear little of 

 canker, unless in places naturally very damp, where more than a fair 

 average of rain falls ; or where, from the prevalence of clouds, there 

 is a deficiency of sunshine. In such places the shoots grow so luxu- 

 riantly during summer, that they are yet soft and spongy, and filled 

 with crude juices in the end of autumn. The frost sets in, freezes 

 these juices, bursts the sap- vessels, and the decay of the shoots, or 

 brown blotches, and ultimate canker, are the consequence. The only 

 preventive in such cases is to plant on hillocks, and in soil made light 

 and poor : the wood will then be less luxuriant and better ripened. 



What has been said respecting the prevention of canker will also 

 apply to its cure. No scrubbing, scraping, or anointing will be of the 

 least use. Cutting down the trees and allowing them to shoot afresh 

 may be of benefit, if the canker has been produced by one very un- 

 favourable season ; grafting them with hardier sorts will succeed, if the 

 evil arises from unfavourableness of climate ; but neither of these 

 methods will be of permanent benefit, when the evil proceeds from bad 

 soil or planting. In such cases, where the trees are very bad, the 

 best method is to destroy them gradually, and plant young ones in a 

 proper manner, leaving some of the old trees until the young ones 

 commence bearing. If the trees are not very old, nor yet too far gone, 

 it will be advisable to take them up carefully, cut away all the cankered 

 wood, plaster up all the wounds with a compound of clay and cow- 

 dung, plant them in fresh soil on hillocks, and give no manure unless 

 what is supplied for mulching, Such trees will generally become 

 quite free of disease and bear splendid crops. A number of years 

 ago, in a large kitchen-garden in the neighbourhood of London, a 

 great number of fruit-trees were found in the different quarters in a 

 miserable state from canker. The gardener appropriated a quarter in 

 the garden for the reception of these trees; had the ground thrown up 

 into wide and high ridges : on the top of these ridges the trees were 

 planted, and in a short time they presented a fine healthy appearance, 

 and were well stocked with good fruit. The soil was a stiff clayey 

 loam. Such radical measures are not only the best antidote to canker, 

 but a certain cure for sterility. 



The gum, by which is meant an extraordinary exudation of that 

 secretion, takes place chiefly in stone-fruit trees, such as the Peach, 



